/*
 *    This program is free software; you can redistribute it and/or modify
 *    it under the terms of the GNU General Public License as published by
 *    the Free Software Foundation; either version 2 of the License, or
 *    (at your option) any later version.
 *
 *    This program is distributed in the hope that it will be useful,
 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *    GNU General Public License for more details.
 *
 *    You should have received a copy of the GNU General Public License
 *    along with this program; if not, write to the Free Software
 *    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

/*
 *    ReferenceInstances.java
 *    Copyright (C) 2001 University of Waikato, Hamilton, New Zealand
 *
 */

package weka.classifiers.trees.adtree;

import weka.core.Instance;
import weka.core.Instances;
import weka.core.RevisionUtils;

/**
 * Simple class that extends the Instances class making it possible to create
 * subsets of instances that reference their source set. Is used by ADTree to
 * make reweighting of instances easy to manage.
 * 
 * @author Richard Kirkby (rkirkby@cs.waikato.ac.nz)
 * @version $Revision: 1.5 $
 */
public class ReferenceInstances extends Instances {

	/** for serialization */
	private static final long serialVersionUID = -8022666381920252997L;

	/**
	 * Creates an empty set of instances.
	 * 
	 * @param dataset
	 *            the instances to get the header information from
	 * @param capacity
	 *            the initial storage capacity of the set
	 */
	public ReferenceInstances(Instances dataset, int capacity) {

		super(dataset, capacity);
	}

	/**
	 * Adds one instance reference to the end of the set. Does not copy instance
	 * before it is added. Increases the size of the dataset if it is not large
	 * enough. Does not check if the instance is compatible with the dataset.
	 * 
	 * @param instance
	 *            the instance to be added
	 */
	public final void addReference(Instance instance) {

		m_Instances.addElement(instance);
	}

	/**
	 * Returns the revision string.
	 * 
	 * @return the revision
	 */
	public String getRevision() {
		return RevisionUtils.extract("$Revision: 1.5 $");
	}
}
